Linux command: crontab

Quick startcrontabCommand, used to schedule cron jobs

Cron jobs are jobs that are scheduled to run at specific intervals. You might make the command execute an operation every hour, every day, or every 2 weeks. Or on the weekend. They are very powerful, especially on servers that perform maintenance and automation.

Thiscrontabcommand is the entry point for using cron jobs.

The first thing you can do is to research which cron jobs you have defined:

crontab -l

You may not have someone like me:

run

crontab -e

Edit the cron job and add a new job.

By default, it will be opened with the default editor, which is usuallyvim. I likenanoIn addition, you can use the following line to use other editors:

EDITOR=nano crontab -e

Now you can add a row for each cron job.

The syntax for defining cron jobs is a bit scary. This is why I usually use websites to help me generate it without errors:https://crontab-generator.org/

You select a time interval for the cron job, and then type the command to be executed.

I choose to run at/Users/flavio/test.shEvery 12 hours. This is the crontab line I need to run:

* */12 * * * /Users/flavio/test.sh >/dev/null 2>&1

I runcrontab -e:

EDITOR=nano crontab -e

Then add the line and pressctrl-Xthen pressysave.

If all goes well, then the cron job will be created:

After this is done, you can view the list of active cron jobs by running the following command:

crontab -l

You can delete running cron jobscrontab -eAgain, delete the line and exit the editor:

ThiscrontabThis command can be used in Linux, macOS, WSL and wherever you have a UNIX environment

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